Semiconductor device and method of forming reconstituted wafer with larger carrier to achieve more eWLB packages per wafer with encapsulant deposited under temperature and pressure

ABSTRACT

A semiconductor wafer has a plurality of semiconductor die distributed over a surface area. The semiconductor die are singulated from the semiconductor wafer. The semiconductor die are mounted to a carrier to form a reconstituted semiconductor wafer. The carrier has a surface area 10-50% larger than the surface area of the semiconductor wafer. The number of semiconductor die mounted to the carrier is greater than a number of semiconductor die singulated from the semiconductor wafer. The reconstituted wafer is mounted within a chase mold. The chase mold is closed with the semiconductor die disposed within a cavity of the chase mold. An encapsulant is dispersed around the semiconductor die within the cavity under temperature and pressure. The encapsulant can be injected into the cavity of the chase mold. The reconstituted wafer is removed from the chase mold. An interconnect structure is formed over the reconstituted wafer.

CLAIM TO DOMESTIC PRIORITY

The present application claims the benefit of U.S. ProvisionalApplication No. 61/544,248, filed Oct. 6, 2011.

FIELD OF THE INVENTION

The present invention relates in general to semiconductor devices and,more particularly, to a semiconductor device and method of forming areconstituted semiconductor wafer with a larger carrier to achieve moreeWLB packages per wafer with an encapsulant deposited under temperatureand pressure.

BACKGROUND OF THE INVENTION

Semiconductor devices are commonly found in modern electronic products.Semiconductor devices vary in the number and density of electricalcomponents. Discrete semiconductor devices generally contain one type ofelectrical component, e.g., light emitting diode (LED), small signaltransistor, resistor, capacitor, inductor, and power metal oxidesemiconductor field effect transistor (MOSFET). Integrated semiconductordevices typically contain hundreds to millions of electrical components.Examples of integrated semiconductor devices include microcontrollers,microprocessors, charged-coupled devices (CCDs), solar cells, anddigital micro-mirror devices (DMDs).

Semiconductor devices perform a wide range of functions such as signalprocessing, high-speed calculations, transmitting and receivingelectromagnetic signals, controlling electronic devices, transformingsunlight to electricity, and creating visual projections for televisiondisplays. Semiconductor devices are found in the fields ofentertainment, communications, power conversion, networks, computers,and consumer products. Semiconductor devices are also found in militaryapplications, aviation, automotive, industrial controllers, and officeequipment.

Semiconductor devices exploit the electrical properties of semiconductormaterials. The atomic structure of semiconductor material allows itselectrical conductivity to be manipulated by the application of anelectric field or base current or through the process of doping. Dopingintroduces impurities into the semiconductor material to manipulate andcontrol the conductivity of the semiconductor device.

A semiconductor device contains active and passive electricalstructures. Active structures, including bipolar and field effecttransistors, control the flow of electrical current. By varying levelsof doping and application of an electric field or base current, thetransistor either promotes or restricts the flow of electrical current.Passive structures, including resistors, capacitors, and inductors,create a relationship between voltage and current necessary to perform avariety of electrical functions. The passive and active structures areelectrically connected to form circuits, which enable the semiconductordevice to perform high-speed calculations and other useful functions.

Semiconductor devices are generally manufactured using two complexmanufacturing processes, i.e., front-end manufacturing, and back-endmanufacturing, each involving potentially hundreds of steps. Front-endmanufacturing involves the formation of a plurality of die on thesurface of a semiconductor wafer. Each semiconductor die is typicallyidentical and contains circuits formed by electrically connecting activeand passive components. Back-end manufacturing involves singulatingindividual semiconductor die from the finished wafer and packaging thedie to provide structural support and environmental isolation. The term“semiconductor die” as used herein refers to both the singular andplural form of the words, and accordingly, can refer to both a singlesemiconductor device and multiple semiconductor devices.

One goal of semiconductor manufacturing is to produce smallersemiconductor devices. Smaller devices typically consume less power,have higher performance, and can be produced more efficiently. Inaddition, smaller semiconductor devices have a smaller footprint, whichis desirable for smaller end products. A smaller semiconductor die sizecan be achieved by improvements in the front-end process resulting insemiconductor die with smaller, higher density active and passivecomponents. Back-end processes may result in semiconductor devicepackages with a smaller footprint by improvements in electricalinterconnection and packaging materials.

A conventional semiconductor wafer typically contains a plurality ofsemiconductor die separated by a saw street. Active and passive circuitsare formed in a surface of each semiconductor die. An interconnectstructure can be formed over the surface of the semiconductor die. Thesemiconductor wafer is singulated into individual semiconductor die foruse in a variety of electronic products. An important aspect ofsemiconductor manufacturing is high yield and corresponding low cost.

SUMMARY OF THE INVENTION

A need exists to efficiently manufacture semiconductor die with anemphasis on high yield and low cost. Accordingly, in one embodiment, thepresent invention is a method of making a semiconductor devicecomprising the steps of providing a semiconductor wafer including aplurality of semiconductor die formed within a surface area of thesemiconductor wafer, singulating the semiconductor die from thesemiconductor wafer, providing a carrier having a surface area largerthan the surface area of the semiconductor wafer, and mounting thesemiconductor die to the carrier to form a reconstituted wafer. A numberof semiconductor die mounted to the carrier is greater than a number ofsemiconductor die singulated from the semiconductor wafer. The methodfurther includes the steps of providing a chase mold, disposing thereconstituted wafer within the chase mold, closing the chase mold withthe semiconductor die disposed within a cavity of the chase mold,dispersing an encapsulant around the semiconductor die within the cavityunder temperature and pressure, removing the reconstituted wafer fromthe chase mold, and forming an interconnect structure over thereconstituted wafer.

In another embodiment, the present invention is a method of making asemiconductor device comprising the steps of providing a plurality ofsemiconductor die, providing a carrier, mounting the semiconductor dieto the carrier to form a reconstituted wafer, providing a chase mold,disposing the reconstituted wafer within the chase mold, closing thechase mold with the semiconductor die and encapsulant disposed within acavity of the chase mold, dispersing an encapsulant around thesemiconductor die within the cavity under temperature and pressure,removing the reconstituted wafer from the chase mold, and forming aninterconnect structure over the reconstituted wafer.

In another embodiment, the present invention is a method of making asemiconductor device comprising the steps of providing a semiconductorwafer including a plurality of semiconductor die formed within a surfacearea of the semiconductor wafer, singulating the semiconductor die fromthe semiconductor wafer, providing a carrier having a surface arealarger than the surface area of the semiconductor wafer, and mountingthe semiconductor die to the carrier to form a reconstituted wafer. Anumber of semiconductor die mounted to the carrier is greater than anumber of semiconductor die singulated from the semiconductor wafer.

In another embodiment, the present invention is a semiconductor devicemade by a process comprising the steps of providing a semiconductorwafer including a plurality of semiconductor die formed within a surfacearea of the semiconductor wafer, singulating the semiconductor die fromthe semiconductor wafer, providing a carrier having a surface arealarger than the surface area of the semiconductor wafer, and mountingthe semiconductor die to the carrier to form a reconstituted wafer. Anumber of semiconductor die mounted to the carrier is greater than anumber of semiconductor die singulated from the semiconductor wafer.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a PCB with different types of packages mounted to itssurface;

FIGS. 2 a-2 c illustrate further detail of the representativesemiconductor packages mounted to the PCB;

FIGS. 3 a-3 c illustrate a semiconductor wafer with a plurality ofsemiconductor die separated by a saw street;

FIGS. 4 a-4 n illustrate a process of forming a reconstitutedsemiconductor wafer with a larger carrier to achieve more eWLB packagesper wafer;

FIG. 5 illustrates the eWLB package with an encapsulant deposited undertemperature and pressure; and

FIG. 6 illustrates the eWLB package with an encapsulant disposed over aback surface of the semiconductor die.

DETAILED DESCRIPTION OF THE DRAWINGS

The present invention is described in one or more embodiments in thefollowing description with reference to the figures, in which likenumerals represent the same or similar elements. While the invention isdescribed in terms of the best mode for achieving the invention'sobjectives, it will be appreciated by those skilled in the art that itis intended to cover alternatives, modifications, and equivalents as maybe included within the spirit and scope of the invention as defined bythe appended claims and their equivalents as supported by the followingdisclosure and drawings.

Semiconductor devices are generally manufactured using two complexmanufacturing processes: front-end manufacturing and back-endmanufacturing. Front-end manufacturing involves the formation of aplurality of die on the surface of a semiconductor wafer. Each die onthe wafer contains active and passive electrical components, which areelectrically connected to form functional electrical circuits. Activeelectrical components, such as transistors and diodes, have the abilityto control the flow of electrical current. Passive electricalcomponents, such as capacitors, inductors, resistors, and transformers,create a relationship between voltage and current necessary to performelectrical circuit functions.

Passive and active components are formed over the surface of thesemiconductor wafer by a series of process steps including doping,deposition, photolithography, etching, and planarization. Dopingintroduces impurities into the semiconductor material by techniques suchas ion implantation or thermal diffusion. The doping process modifiesthe electrical conductivity of semiconductor material in active devices,transforming the semiconductor material into an insulator, conductor, ordynamically changing the semiconductor material conductivity in responseto an electric field or base current. Transistors contain regions ofvarying types and degrees of doping arranged as necessary to enable thetransistor to promote or restrict the flow of electrical current uponthe application of the electric field or base current.

Active and passive components are formed by layers of materials withdifferent electrical properties. The layers can be formed by a varietyof deposition techniques determined in part by the type of materialbeing deposited. For example, thin film deposition can involve chemicalvapor deposition (CVD), physical vapor deposition (PVD), electrolyticplating, and electroless plating processes. Each layer is generallypatterned to form portions of active components, passive components, orelectrical connections between components.

The layers can be patterned using photolithography, which involves thedeposition of light sensitive material, e.g., photoresist, over thelayer to be patterned. A pattern is transferred from a photomask to thephotoresist using light. In one embodiment, the portion of thephotoresist pattern subjected to light is removed using a solvent,exposing portions of the underlying layer to be patterned. In anotherembodiment, the portion of the photoresist pattern not subjected tolight, the negative photoresist, is removed using a solvent, exposingportions of the underlying layer to be patterned. The remainder of thephotoresist is removed, leaving behind a patterned layer. Alternatively,some types of materials are patterned by directly depositing thematerial into the areas or voids formed by a previous deposition/etchprocess using techniques such as electroless and electrolytic plating.

Depositing a thin film of material over an existing pattern canexaggerate the underlying pattern and create a non-uniformly flatsurface. A uniformly flat surface is required to produce smaller andmore densely packed active and passive components. Planarization can beused to remove material from the surface of the wafer and produce auniformly flat surface. Planarization involves polishing the surface ofthe wafer with a polishing pad. An abrasive material and corrosivechemical are added to the surface of the wafer during polishing. Thecombined mechanical action of the abrasive and corrosive action of thechemical removes any irregular topography, resulting in a uniformly flatsurface.

Back-end manufacturing refers to cutting or singulating the finishedwafer into the individual die and then packaging the die for structuralsupport and environmental isolation. To singulate the semiconductor die,the wafer is scored and broken along non-functional regions of the wafercalled saw streets or scribes. The wafer is singulated using a lasercutting tool or saw blade. After singulation, the individualsemiconductor die are mounted to a package substrate that includes pinsor contact pads for interconnection with other system components.Contact pads formed over the semiconductor die are then connected tocontact pads within the package. The electrical connections can be madewith solder bumps, stud bumps, conductive paste, or wirebonds. Anencapsulant or other molding material is deposited over the package toprovide physical support and electrical isolation. The finished packageis then inserted into an electrical system and the functionality of thesemiconductor device is made available to the other system components.

FIG. 1 illustrates electronic device 50 having a chip carrier substrateor printed circuit board (PCB) 52 with a plurality of semiconductorpackages mounted on its surface. Electronic device 50 can have one typeof semiconductor package, or multiple types of semiconductor packages,depending on the application. The different types of semiconductorpackages are shown in FIG. 1 for purposes of illustration.

Electronic device 50 can be a stand-alone system that uses thesemiconductor packages to perform one or more electrical functions.Alternatively, electronic device 50 can be a subcomponent of a largersystem. For example, electronic device 50 can be part of a cellularphone, personal digital assistant (PDA), digital video camera (DVC), orother electronic communication device. Alternatively, electronic device50 can be a graphics card, network interface card, or other signalprocessing card that can be inserted into a computer. The semiconductorpackage can include microprocessors, memories, application specificintegrated circuits (ASIC), logic circuits, analog circuits, RFcircuits, discrete devices, or other semiconductor die or electricalcomponents. Miniaturization and weight reduction are essential for theseproducts to be accepted by the market. The distance betweensemiconductor devices must be decreased to achieve higher density.

In FIG. 1, PCB 52 provides a general substrate for structural supportand electrical interconnect of the semiconductor packages mounted on thePCB. Conductive signal traces 54 are formed over a surface or withinlayers of PCB 52 using evaporation, electrolytic plating, electrolessplating, screen printing, or other suitable metal deposition process.Signal traces 54 provide for electrical communication between each ofthe semiconductor packages, mounted components, and other externalsystem components. Traces 54 also provide power and ground connectionsto each of the semiconductor packages.

In some embodiments, a semiconductor device has two packaging levels.First level packaging is a technique for mechanically and electricallyattaching the semiconductor die to an intermediate carrier. Second levelpackaging involves mechanically and electrically attaching theintermediate carrier to the PCB. In other embodiments, a semiconductordevice may only have the first level packaging where the die ismechanically and electrically mounted directly to the PCB.

For the purpose of illustration, several types of first level packaging,including bond wire package 56 and flip chip 58, are shown on PCB 52.Additionally, several types of second level packaging, including ballgrid array (BGA) 60, bump chip carrier (BCC) 62, dual in-line package(DIP) 64, land grid array (LGA) 66, multi-chip module (MCM) 68, quadflat non-leaded package (QFN) 70, and quad flat package 72, are shownmounted on PCB 52. Depending upon the system requirements, anycombination of semiconductor packages, configured with any combinationof first and second level packaging styles, as well as other electroniccomponents, can be connected to PCB 52. In some embodiments, electronicdevice 50 includes a single attached semiconductor package, while otherembodiments call for multiple interconnected packages. By combining oneor more semiconductor packages over a single substrate, manufacturerscan incorporate pre-made components into electronic devices and systems.Because the semiconductor packages include sophisticated functionality,electronic devices can be manufactured using cheaper components and astreamlined manufacturing process. The resulting devices are less likelyto fail and less expensive to manufacture resulting in a lower cost forconsumers.

FIGS. 2 a-2 c show exemplary semiconductor packages. FIG. 2 aillustrates further detail of DIP 64 mounted on PCB 52. Semiconductordie 74 includes an active region containing analog or digital circuitsimplemented as active devices, passive devices, conductive layers, anddielectric layers formed within the die and are electricallyinterconnected according to the electrical design of the die. Forexample, the circuit can include one or more transistors, diodes,inductors, capacitors, resistors, and other circuit elements formedwithin the active region of semiconductor die 74. Contact pads 76 areone or more layers of conductive material, such as aluminum (Al), copper(Cu), tin (Sn), nickel (Ni), gold (Au), or silver (Ag), and areelectrically connected to the circuit elements formed withinsemiconductor die 74. During assembly of DIP 64, semiconductor die 74 ismounted to an intermediate carrier 78 using a gold-silicon eutecticlayer or adhesive material such as thermal epoxy or epoxy resin. Thepackage body includes an insulative packaging material such as polymeror ceramic. Conductor leads 80 and bond wires 82 provide electricalinterconnect between semiconductor die 74 and PCB 52. Encapsulant 84 isdeposited over the package for environmental protection by preventingmoisture and particles from entering the package and contaminatingsemiconductor die 74 or bond wires 82.

FIG. 2 b illustrates further detail of BCC 62 mounted on PCB 52.Semiconductor die 88 is mounted to carrier 90 using an underfill orepoxy-resin adhesive material 92. Bond wires 94 provide first levelpackaging interconnect between contact pads 96 and 98. Molding compoundor encapsulant 100 is deposited over semiconductor die 88 and bond wires94 to provide physical support and electrical isolation for the device.Contact pads 102 are formed over a surface of PCB 52 using a suitablemetal deposition process such as electrolytic plating or electrolessplating to prevent oxidation. Contact pads 102 are electricallyconnected to one or more conductive signal traces 54 in PCB 52. Bumps104 are formed between contact pads 98 of BCC 62 and contact pads 102 ofPCB 52.

In FIG. 2 c, semiconductor die 58 is mounted face down to intermediatecarrier 106 with a flip chip style first level packaging. Active region108 of semiconductor die 58 contains analog or digital circuitsimplemented as active devices, passive devices, conductive layers, anddielectric layers formed according to the electrical design of the die.For example, the circuit can include one or more transistors, diodes,inductors, capacitors, resistors, and other circuit elements withinactive region 108. Semiconductor die 58 is electrically and mechanicallyconnected to carrier 106 through bumps 110.

BGA 60 is electrically and mechanically connected to PCB 52 with a BGAstyle second level packaging using bumps 112. Semiconductor die 58 iselectrically connected to conductive signal traces 54 in PCB 52 throughbumps 110, signal lines 114, and bumps 112. A molding compound orencapsulant 116 is deposited over semiconductor die 58 and carrier 106to provide physical support and electrical isolation for the device. Theflip chip semiconductor device provides a short electrical conductionpath from the active devices on semiconductor die 58 to conductiontracks on PCB 52 in order to reduce signal propagation distance, lowercapacitance, and improve overall circuit performance. In anotherembodiment, the semiconductor die 58 can be mechanically andelectrically connected directly to PCB 52 using flip chip style firstlevel packaging without intermediate carrier 106.

FIG. 3 a shows a semiconductor wafer 120 with a base substrate material122, such as silicon, germanium, gallium arsenide, indium phosphide, orsilicon carbide, for structural support. A plurality of semiconductordie or components 124 is formed on wafer 120 separated by a non-active,inter-die wafer area or saw street 126 as described above. Saw street126 provides cutting areas to singulate semiconductor wafer 120 intoindividual semiconductor die 124.

FIG. 3 b shows a cross-sectional view of a portion of semiconductorwafer 120. Each semiconductor die 124 has a back surface 128 and activesurface 130 containing analog or digital circuits implemented as activedevices, passive devices, conductive layers, and dielectric layersformed within the die and electrically interconnected according to theelectrical design and function of the die. For example, the circuit mayinclude one or more transistors, diodes, and other circuit elementsformed within active surface 130 to implement analog circuits or digitalcircuits, such as digital signal processor (DSP), ASIC, memory, or othersignal processing circuit. Semiconductor die 124 may also containintegrated passive devices (IPDs), such as inductors, capacitors, andresistors, for RF signal processing. In one embodiment, semiconductordie 124 is a flip chip type device.

A support carrier or laminated dicing tape 134 is applied to backsurface 128 of semiconductor wafer 120. Laminated dicing tape 134provides support for semiconductor wafer 120 during subsequentmanufacturing steps and singulation into individual semiconductor die124.

An electrically conductive layer 132 is formed over active surface 130using PVD, CVD, electrolytic plating, electroless plating process, orother suitable metal deposition process. Conductive layer 132 can be oneor more layers of Al, Cu, Sn, Ni, Au, Ag, or other suitable electricallyconductive material. Conductive layer 132 operates as contact padselectrically connected to the circuits on active surface 130. Contactpads 132 can be disposed side-by-side a first distance from the edge ofsemiconductor die 124, as shown in FIG. 3 b. Alternatively, contact pads132 can be offset in multiple rows such that a first row of contact padsis disposed a first distance from the edge of the die, and a second rowof contact pads alternating with the first row is disposed a seconddistance from the edge of the die.

In FIG. 3 c, semiconductor wafer 120 is singulated through saw street126 using a saw blade or laser cutting tool 136 into individualsemiconductor die 124. Lamination dicing tape 134 is removed.

FIGS. 4 a-4 n illustrate, in relation to FIGS. 1 and 2 a-2 c, a processof forming a reconstituted semiconductor wafer with a larger carrier toachieve more eWLB packages per wafer with an encapsulant deposited undertemperature and pressure. FIG. 4 a shows a temporary substrate orcarrier 140 containing sacrificial base material such as silicon,polymer, beryllium oxide, glass, or other suitable low-cost, rigidmaterial for structural support. Alternatively, carrier 140 can bemetal, such as nickel, platinum, copper, copper alloys (including one ormore elements of nickel, iron, zinc, tin, chromium, silver, andphosphorous), or other suitable rigid material for structural support.An interface layer or double-sided tape 142 is formed over carrier 140as a temporary adhesive bonding film, etch-stop layer, or release layer.

Carrier 140 has a larger diameter and surface area as compared to thediameter and surface area of semiconductor wafer 120. In one embodiment,carrier 140 has a surface area that is 10-50% greater than the surfacearea of semiconductor wafer 120. If semiconductor wafer 120 has adiameter of 300 millimeters (mm), then carrier 140 is made with adiameter of 310-350 mm. In other cases, if semiconductor wafer 120 has adiameter of 150 mm, then carrier 140 is made with a diameter of 180 mm,giving a 44% increase in surface area. If semiconductor wafer 120 has adiameter of 200 mm, then carrier 140 is made with a diameter of 240 mm,giving a 44% increase in surface area. If semiconductor wafer 120 has adiameter of 450 mm, then carrier 140 is made with a diameter of 550 mm,giving a 49% increase in surface area.

In FIG. 4 b, semiconductor die 124 from FIGS. 3 a-3 c is positioned overand mounted to carrier 140 using a pick and place operation with activesurface 130 oriented toward the carrier. FIG. 4 c shows semiconductordie 124 mounted to carrier 140 as reconstituted semiconductor wafer 146.The reconstituted semiconductor wafer 146 has a diameter and surfacearea larger than the diameter and surface area of semiconductor wafer120. In one embodiment, reconstituted semiconductor wafer 146 has asurface area that is 10-50% greater than the surface area ofsemiconductor wafer 120. The larger surface area of carrier 140 andreconstituted semiconductor wafer 146 accommodates more semiconductordie 124 and lowers manufacturing cost as more semiconductor die 124 areprocessed per reconstituted semiconductor wafer. The number ofsemiconductor die 124 mounted to carrier 140 is greater than the numberof semiconductor die 124 singulated from semiconductor wafer 120. In oneembodiment, the number of semiconductor die 124 mounted to carrier 140is 10-50% more than the number of semiconductor die 124 singulated fromsemiconductor wafer 120.

FIG. 4 d shows a chase mold 150 having an upper mold support 152 andlower mold support 154. Upper mold support 152 has a cavity 156 forcontaining semiconductor die 124 and encapsulant or molding compound.Lower mold support 152 includes a plurality of spring-loaded lifter pins158. The reconstituted semiconductor wafer 146 is placed over lower moldsupport 154 with the surface of carrier 140, opposite semiconductor die124, contacting spring-loaded lifter pins 158. The spring-loaded lifterpins 158 in a relaxed or non-compressed state maintain a separation bydistance D between carrier 140 and surface 160 of lower mold support154. In one embodiment, the separation distance D is 0.5 mm to avoidinitial heat transfer to reconstituted semiconductor wafer 146.

In FIG. 4 e, a volume of encapsulant or molding compound 162 isdeposited over semiconductor die 124 and interface layer 142 of carrier140. Encapsulant 162 can be a polymer composite material, such as epoxyresin with filler, epoxy acrylate with filler, or polymer with properfiller. The volume of encapsulant 162 is measured according to the spacerequirements of cavity 156 less the area occupied by semiconductor die124. In one embodiment, the volume of encapsulant 162 ranges between20-250 grams for a carrier diameter of 300 mm.

The upper mold support 152 and lower mold support 154 are broughttogether under pressure with force F to close chase mold 150 withsemiconductor die 124 and encapsulant 162 disposed within cavity 156, asshown in FIG. 4 f. As interface layer 142 contacts surface 164 of uppermold support 152, spring-loaded lifter pins 158 begin to compress. Themovement of lower mold support 154 towards upper mold support 152continues until opposing surfaces of interface layer 142 and carrier 140contact surface 160 of lower mold support 154 and surface 164 of uppermold support 152. Spring-loaded lifter pins 158 are fully compressedunder a clamping force F of 50-500 kilo-Newtons (kN) between upper moldsupport 152 and lower mold support 154.

Heat is transferred through upper mold support 152 and lower moldsupport 154 to bring encapsulant 162 to a viscous state. Encapsulant 162is evenly dispersed and uniformly distributed under an elevatedtemperature within cavity 156 around semiconductor die 124. In oneembodiment, the molding temperature ranges from 80-150° C. with amolding time of 250-1000 seconds. The molding cure temperature rangesfrom 100-180° C. with a molding cure time of 20-120 minutes. Thetemperature and pressure within chase mold 150 provides a planarencapsulant coverage with less warpage. The thickness of encapsulant 162remains uniform, e.g. less than 5% deviation, across reconstitutedsemiconductor wafer 146.

In another embodiment, continuing from FIG. 4 d, chase mold 170 has anupper mold support 172 and lower mold support 174, as shown in FIG. 4 g.Upper mold support 172 has a plurality of inlets 176 into cavity 178 forcontaining semiconductor die 124 and encapsulant or molding compound.Lower mold support 174 includes a plurality of spring-loaded lifter pins180. The reconstituted semiconductor wafer 146 is placed over lower moldsupport 174 with the lower surface of carrier 140 contactingspring-loaded lifter pins 180. The spring-loaded lifter pins 180 in arelaxed or non-compressed state maintain a separation by distance Dbetween carrier 140 and surface 182 of lower mold support 174. In oneembodiment, the separation distance D is 0.5 mm to avoid initial heattransfer to reconstituted semiconductor wafer 146.

The upper mold support 172 and lower mold support 174 are broughttogether under pressure with force F, as shown in FIG. 4 h, to closechase mold 170 with semiconductor die 124 disposed within cavity 178. Asinterface layer 142 contacts surface 184 of upper mold support 172,spring-loaded lifter pins 180 begin to compress. The movement of lowermold support 174 towards upper mold support 172 continues until opposingsurfaces of interface layer 142 and carrier 140 contact surface 182 oflower mold support 174 and surface 184 of upper mold support 172.Spring-loaded lifter pins 180 are fully compressed under a clampingforce F of 50-500 kN between upper mold support 172 and lower moldsupport 174.

A volume of encapsulant or molding compound 186 is injected fromdispenser 188 under an elevated temperature and pressure through inlet176 a into cavity 178 and over semiconductor die 124 and interface layer142 of carrier 140. Inlet 176 b can be exhaust port for excessencapsulant 186. Encapsulant 186 can be a polymer composite material,such as epoxy resin with filler, epoxy acrylate with filler, or polymerwith proper filler. The volume of encapsulant 186 is measured accordingto the space requirements of cavity 178 less the area occupied bysemiconductor die 124. In one embodiment, the volume of encapsulant 186ranges between 20-250 grams for a carrier diameter of 300 mm.Encapsulant 186 is evenly dispersed and uniformly distributed under anelevated temperature within cavity 178 around semiconductor die 124. Inone embodiment, the molding temperature ranges from 80-150° C. with amolding time of 250-1000 seconds. The molding cure temperature rangesfrom 100-180° C. with a molding cure time of 20-120 minutes. Thethickness of encapsulant 186 remains uniform, e.g. less than 5%deviation, across reconstituted semiconductor wafer 146.

FIG. 4 i shows reconstituted semiconductor wafer 146 removed from thechase mold. In FIG. 4 j, a portion of encapsulant 162 is optionallyremoved by grinder 190 to planarize the encapsulant with back surface128 of semiconductor die 124. Encapsulant 162 can also be planarized byan etching process or CMP.

Carrier 140 and interface layer 142 are removed by chemical etching,mechanical peeling, CMP, mechanical grinding, thermal bake, UV light,laser scanning, or wet stripping to expose conductive layer 132 andactive surface 130 of semiconductor die 124 and encapsulant 162. FIG. 4k shows a plan view of reconstituted semiconductor wafer 146 withsemiconductor die 124 embedded within encapsulant 162.

FIG. 4 l shows a temporary substrate or carrier 192 containingsacrificial base material such as silicon, polymer, beryllium oxide, orother suitable low-cost, rigid material for structural support. Aninterface layer or double-sided tape 194 is formed over carrier 192 as atemporary adhesive bonding film or etch-stop layer. The reconstitutedsemiconductor wafer 146 with encapsulant 162 is mounted to interfacelayer 194 over carrier 192 with active surface 130 oriented away fromthe carrier.

In FIG. 4 m, an insulating or passivation layer 200 is formed overencapsulant 162, active surface 130, and conductive layer 132 using PVD,CVD, printing, spin coating, spray coating, lamination, sintering orthermal oxidation. The insulating layer 200 contains one or more layersof silicon dioxide (SiO2), silicon nitride (Si3N4), silicon oxynitride(SiON), tantalum pentoxide (Ta2O5), aluminum oxide (Al2O3), or othermaterial having similar insulating and structural properties. A portionof insulating layer 200 is removed by an etching process through apatterned photoresist layer to expose conductive layer 132.

An electrically conductive layer 202 is formed insulating layer 200 andconductive layer 132 using a patterning and metal deposition processsuch as printing, PVD, CVD, sputtering, electrolytic plating, andelectroless plating. Conductive layer 202 can be one or more layers ofAl, Cu, Sn, Ti, Ni, Au, Ag, or other suitable electrically conductivematerial. A portion of conductive layer 202 extends horizontally alonginsulating layer 200 and parallel to active surface 130 of semiconductordie 124 to laterally redistribute the electrical interconnect toconductive layer 132. Conductive layer 202 operates as a fan-outredistribution layer (RDL) for the electrical signals of semiconductordie 124. A portion of conductive layer 202 is electrically connected toconductive layer 132. Other portions of conductive layer 202 areelectrically common or electrically isolated depending on theconnectivity of semiconductor die 124.

In FIG. 4 n, an insulating or passivation layer 204 is formed overinsulating layer 200 and conductive layer 202 using PVD, CVD, printing,spin coating, spray coating, screen printing or lamination. Theinsulating layer 204 can be one or more layers of SiO2, Si3N4, SiON,Ta2O5, Al2O3, or other material having similar insulating and structuralproperties. A portion of insulating layer 204 is removed by an etchingprocess with a patterned photoresist layer to expose conductive layer202.

An electrically conductive bump material is deposited over the exposedconductive layer 202 using an evaporation, electrolytic plating,electroless plating, ball drop, or screen printing process. The bumpmaterial can be Al, Sn, Ni, Au, Ag, Pb, Bi, Cu, solder, and combinationsthereof, with an optional flux solution. For example, the bump materialcan be eutectic Sn/Pb, high-lead solder, or lead-free solder. The bumpmaterial is bonded to conductive layer 202 using a suitable attachmentor bonding process. In one embodiment, the bump material is reflowed byheating the material above its melting point to form balls or bumps 206.In some applications, bumps 206 are reflowed a second time to improveelectrical contact to conductive layer 202. Bumps 206 can also becompression bonded to conductive layer 202. Bumps 206 represent one typeof interconnect structure that can be formed over conductive layer 202.The interconnect structure can also use stud bump, micro bump, or otherelectrical interconnect.

The combination of insulating layers 200 and 204, conductive layers 202,and bumps 206 constitute a build-up interconnect structure 208 formedover semiconductor die 124 and encapsulant 162. Additional insulatinglayers and RDLs can be formed in build-up interconnect structure 208 forinterconnection to semiconductor die 124.

The reconstituted semiconductor wafer 146 is singulated throughencapsulant 162 and build-up interconnect structure 208 with saw bladeor laser cutting tool 210 into individual fan-out embedded wafer levelball grid array (eWLB) package 212. Carrier 192 and interface layer 194are removed by chemical etching, mechanical peeling, CMP, mechanicalgrinding, thermal bake, UV light, laser scanning, or wet stripping.

FIG. 5 shows the fan-out eWLB 212 after singulation and removal ofcarrier 192 and interface layer 194. Conductive layer 132 ofsemiconductor die 124 is electrically connected to conductive layer 202and bumps 206. The fan-out eWLB 212 is formed from a reconstitutedsemiconductor wafer 146 having a diameter and surface area larger thanthe diameter and surface area of semiconductor wafer 120. In oneembodiment, reconstituted semiconductor wafer 146 has a surface areathat is 10-50% greater than the surface area of semiconductor wafer 120.The larger surface area of carrier 140 and reconstituted semiconductorwafer 146 accommodates more semiconductor die 124 and lowersmanufacturing cost as more semiconductor die 124 are processed perreconstituted semiconductor wafer. Encapsulant 162 is formed undertemperature and pressure within chase mold 150 for a planar encapsulantcoverage with less warpage. The thickness of encapsulant 162 remainsuniform, e.g. less than 5% deviation, across reconstituted semiconductorwafer 146.

In summary, semiconductor wafer 120 includes a plurality ofsemiconductor die 124 formed within a surface area of the semiconductorwafer. Semiconductor die 124 are singulated from semiconductor wafer120. A carrier 140 has a surface area larger than the surface area ofsemiconductor wafer 120. The surface area of carrier 140 is 10-50%greater than the surface area of semiconductor wafer 120. Semiconductordie 124 are mounted to carrier 140 to form reconstituted semiconductorwafer 146. The number of semiconductor die 124 mounted to carrier 140 isgreater than the number of semiconductor die 124 singulated fromsemiconductor wafer 120. The reconstituted semiconductor wafer 146 isdisposed within chase mold 150. Chase mold 150 is closed withsemiconductor die 124 disposed within cavity 156 of the chase mold. Inone embodiment, upper mold support 152 includes cavity 156. A lower moldsupport 154 has spring-loaded lifter pins 158. The reconstitutedsemiconductor wafer 146 is disposed over spring-loaded lifter pins 158.Encapsulant 162 is deposited over reconstituted semiconductor wafer 146.Chase mold 150 is closed so that lower mold support 154 and upper moldsupport 152 contact carrier 140 under pressure to enclose semiconductordie 124 and encapsulant 162 within cavity 156 of the upper mold supportand compress spring-loaded lifter pins 158. Encapsulant 162 is dispersedaround semiconductor die 124 within cavity 156 under an elevatedtemperature and pressure. Alternatively, upper mold support 172 includesinlets 176 and cavity 178. Lower mold support 174 has spring-loadedlifter pins 180. The reconstituted semiconductor wafer 146 is disposedover spring-loaded lifter pins 180. Chase mold 170 is closed so thatlower mold support 174 and upper mold support 172 contact carrier 140with semiconductor die 124 disposed within cavity 178 of the upper moldsupport and compress spring-loaded lifter pins 180. Encapsulant 186 isinjected into cavity 180 through inlets 176. Encapsulant 186 isdispersed under an elevated temperature and pressure aroundsemiconductor die 124. The reconstituted semiconductor wafer 146 isremoved from the chase mold. Encapsulant 162 is planarized to expose aback surface 128 of semiconductor die 124. An interconnect structure 208is formed over reconstituted semiconductor wafer 146. The interconnectstructure 208 includes an insulating layer 200 formed over a surface ofreconstituted semiconductor wafer 146. Conductive layer 202 is formedover insulating layer 200. The insulating layer 204 is formed overinsulating layer 200 and conductive layer 202.

FIG. 6 shows an embodiment of fan-out eWLB 214 with encapsulant 162disposed over back surface 128 of semiconductor die 124, i.e. withoutthe optional planarization of the encapsulant shown in FIG. 4 j.Conductive layer 132 of semiconductor die 124 is electrically connectedto conductive layer 202 and bumps 206. The fan-out eWLB 214 is formedfrom a reconstituted semiconductor wafer 146 having a diameter andsurface area larger than the diameter and surface area of semiconductorwafer 120. In one embodiment, reconstituted semiconductor wafer 146 hasa surface area that is 10-50% greater than the surface area ofsemiconductor wafer 120. The larger surface area of carrier 140 andreconstituted semiconductor wafer 146 accommodates more semiconductordie 124 and lowers manufacturing cost as more semiconductor die 124 areprocessed per reconstituted semiconductor wafer. Encapsulant 162 isformed under temperature and pressure within chase mold 150 for a planarencapsulant coverage with less warpage. The thickness of encapsulant 162remains uniform, e.g. less than 5% deviation, across reconstitutedsemiconductor wafer 146.

While one or more embodiments of the present invention have beenillustrated in detail, the skilled artisan will appreciate thatmodifications and adaptations to those embodiments may be made withoutdeparting from the scope of the present invention as set forth in thefollowing claims.

What is claimed:
 1. A method of making a semiconductor device,comprising: providing a semiconductor wafer including a plurality ofsemiconductor die formed within a surface area of the semiconductorwafer; singulating the semiconductor die from the semiconductor wafer;providing a carrier including a surface area larger than the surfacearea of the semiconductor wafer; disposing the semiconductor die overthe carrier to form a reconstituted wafer, wherein a number ofsemiconductor die disposed side-by-side and non-overlapping over thecarrier is greater than the total number of semiconductor die singulatedfrom the semiconductor wafer; providing a chase mold; disposing thereconstituted wafer within the chase mold; closing the chase mold withthe semiconductor die disposed within a cavity of the chase mold;dispersing an encapsulant around the semiconductor die within the cavityunder temperature and pressure; removing the reconstituted wafer fromthe chase mold; and forming an interconnect structure over thereconstituted wafer.
 2. The method of claim 1, further includingplanarizing the encapsulant to expose a surface of the semiconductordie.
 3. The method of claim 1, wherein the surface area of the carrieris 10-50% greater than the surface area of the semiconductor wafer. 4.The method of claim 1, wherein providing the chase mold includes:providing an upper mold support including the cavity; providing a lowermold support with spring-loaded lifter pins; disposing the reconstitutedwafer over the spring-loaded lifter pins; depositing the encapsulantover the reconstituted wafer; closing the chase mold to compress thespring-loaded lifter pins which apply pressure to hold the upper moldsupport and lower mold support against opposing surfaces of thereconstituted wafer with the semiconductor die disposed within thecavity; and dispersing the encapsulant under an elevated temperaturearound the semiconductor die.
 5. The method of claim 1, furtherincluding: providing an upper mold support including an inlet and thecavity; providing a lower mold support with spring-loaded lifter pins;disposing the reconstituted wafer over the spring-loaded lifter pins;closing the chase mold to compress the spring-loaded lifter pins whichapply pressure to hold the upper mold support and lower mold supportagainst opposing surfaces of the reconstituted wafer with thesemiconductor die disposed within the cavity; and injecting theencapsulant under an elevated temperature through the inlet into thecavity around the semiconductor die.
 6. The method of claim 1, whereinforming the interconnect structure includes: forming a first insulatinglayer over a surface of the reconstituted wafer; forming a conductivelayer over the first insulating layer; and forming a second insulatinglayer over the first insulating layer and conductive layer.
 7. A methodof making a semiconductor device, comprising: providing a semiconductorwafer including a plurality of semiconductor die formed within a surfacearea of the semiconductor wafer; singulating the semiconductor die fromthe semiconductor wafer; providing a carrier including a surface arealarger than the surface area of the semiconductor wafer; disposing thesemiconductor die over a surface of the carrier to form a reconstitutedwafer, wherein a number of semiconductor die disposed side-by-side andnon-overlapping over the carrier is greater than the total number ofsemiconductor die singulated from the semiconductor wafer; providing achase mold including an upper mold support and lower mold support withspring-loaded lifter pins; disposing the reconstituted wafer within thechase mold over the lower mold support and spring-loaded lifter pins;closing the chase mold to compress the spring-loaded lifter pins whichapply pressure to hold the upper mold support and lower mold supportagainst opposing surfaces of the reconstituted wafer with thesemiconductor die disposed within a cavity of the chase mold; providingan encapsulant around the semiconductor die within the cavity undertemperature and pressure; removing the reconstituted wafer from thechase mold; and forming an interconnect structure over the reconstitutedwafer.
 8. The method of claim 7, wherein the surface area of the carrieris 10-50% greater than the surface area of the semiconductor wafer. 9.The method of claim 7, further including planarizing the encapsulant toexpose a surface of the semiconductor die.
 10. The method of claim 7,wherein forming the interconnect structure includes: forming a firstinsulating layer over a surface of the reconstituted wafer; forming aconductive layer over the first insulating layer; and forming a secondinsulating layer over the first insulating layer and conductive layer.11. A method of making a semiconductor device, comprising: providing asemiconductor wafer including a plurality of semiconductor die formedwithin a surface area of the semiconductor wafer; singulating thesemiconductor die from the semiconductor wafer; providing a carrierincluding a surface area larger than the surface area of thesemiconductor wafer; and disposing the semiconductor die over thecarrier to form a reconstituted wafer, wherein a number of semiconductordie disposed side-by-side and non-overlapping over the carrier isgreater than the total number of semiconductor die singulated from thesemiconductor wafer.
 12. The method of claim 11, wherein the surfacearea of the carrier is 10-50% greater than the surface area of thesemiconductor wafer.
 13. The method of claim 11, further including:providing a chase mold; disposing the reconstituted wafer within thechase mold; closing the chase mold with the semiconductor die disposedwithin a cavity of the chase mold; dispersing an encapsulant around thesemiconductor die within the cavity under temperature and pressure;removing the reconstituted wafer from the chase mold; and forming aninterconnect structure over the reconstituted wafer.
 14. The method ofclaim 13, further including planarizing the encapsulant to expose asurface of the semiconductor die.
 15. The method of claim 13, whereinproviding the chase mold includes: providing an upper mold supportincluding the cavity; providing a lower mold support with spring-loadedlifter pins; disposing the reconstituted wafer over the spring-loadedlifter pins; depositing the encapsulant over the reconstituted wafer;closing the chase mold to compress the spring-loaded lifter pins whichapply pressure to hold the upper mold support and lower mold supportagainst opposing surfaces of the reconstituted wafer with thesemiconductor die disposed within the cavity; and dispersing theencapsulant under an elevated temperature around the semiconductor die.16. The method of claim 13, further including: providing an upper moldsupport including an inlet and the cavity; providing a lower moldsupport with spring-loaded lifter pins; disposing the reconstitutedwafer over the spring-loaded lifter pins; closing the chase mold tocompress the spring-loaded lifter pins which apply pressure to hold theupper mold support and lower mold support against opposing surfaces ofthe reconstituted wafer with the semiconductor die disposed within thecavity; and injecting the encapsulant under an elevated temperaturethrough the inlet into the cavity around the semiconductor die.
 17. Themethod of claim 13, wherein forming the interconnect structure includes:forming a first insulating layer over a surface of the reconstitutedwafer; forming a conductive layer over the first insulating layer; andforming a second insulating layer over the first insulating layer andconductive layer.
 18. A method of making a semiconductor device,comprising: providing a semiconductor wafer including a plurality ofsemiconductor die; singulating the semiconductor die from thesemiconductor wafer; providing a carrier; and disposing thesemiconductor die over a surface of the carrier to form a reconstitutedwafer, wherein a number of semiconductor die disposed side-by-side andnon-overlapping over contacting the surface of the carrier is greaterthan the total number of semiconductor die singulated from thesemiconductor wafer.
 19. The method of claim 18, wherein a surface areaof the carrier is 10-50% greater than a surface area of thesemiconductor wafer.
 20. The method of claim 18, further includingplanarizing the encapsulant to expose a surface of the semiconductordie.
 21. The method of claim 18, further including forming aninterconnect structure over the reconstituted wafer.
 22. The method ofclaim 21, wherein forming the interconnect structure includes: forming afirst insulating layer over a surface of the reconstituted wafer;forming a conductive layer over the first insulating layer; and forminga second insulating layer over the first insulating layer and conductivelayer.